Mellow,We love trearrdur,but if the wether is right then you will que for the slip and its tidal and very steep.
Holyhead has a brill slip almost anytime exept at low water big springs.They say you need be a member,But here is the shake.
If you ring the club at Holyhead and offer to make an RNLI donation they will proberbly sort you out,If they like you.
If I remember correctly the guy to talk to is Tobby ? the boat man,He is a ribster himself,and a real nice guy.
He will be at the club house or Marina most days
Have a great time and good luck.